1. Field of the Invention
The present invention relates to apparatus and method for processing information and apparatus and method for displaying image and, more particularly, relates to apparatus and method for processing information and apparatus and method for displaying image adapted such that date data retained in a database of the dates at which map data of various areas were registered therein are compared with date data corresponding to the map data retained in an apparatus utilized by the user and, on the basis of the comparison, the map data and the date data in the apparatus utilized by the user are each updated automatically.
2. Description of the Related Art
Recently, car navigation systems utilizing the GPS (Global Positioning System) in which a radio wave from a specific artificial satellite is received and the latitude and longitude of a position are calculated have come into wide use. There are many of types of such car navigation systems that read out map data of a specific area from a CD (Compact Disk)-ROM with map data recorded therein by playing back the same with the use of a CD-ROM drive and have the image of the map corresponding to the map data displayed thereon.
However, in order to use the latest map data when utilizing map data recorded in such a CD-ROM, it becomes necessary to buy from time to time the latest version of the CD-ROM with the map data recorded therein. Therefore, such problems arise that the cost therefor increases, the exchanging operation of the CD-ROM becomes necessary, and, even if a latest version is obtained, a certain time period has already elapsed for making up the CD-ROM at the time when it is released, namely, it is difficult to write the map data which were changed while a latest version of the CD-ROM was being manufactured into the latest version.
Accordingly, there is proposed a car navigation system which allows the latest map data to be read out from a specific map database center through a specific transmission medium. In this type of the car navigation system, map data designated by the user is read out from the map database center through, for example, a public telephone line, portable telephone, modem, and the like, and stored into memory.
By adapting such that the latest map data is read out from a specific map database center as described above, the operation for exchanging the CD-ROM can be eliminated. Further, by having the map data in the map database center updated when a change occurs in the map, the car navigation system is enabled, upon selection of such map data by the user, to read out the selected map data and, hence, it becomes possible to provide the car navigation system with more recent map data than that distributed by a CD-ROM.
However, if it is practiced that the map data designated by the user is read out from the map database and stored into memory, there arises a problem that such an operation must be performed every time as to select the map data of the area required by the user out of a huge map database covering the whole of the country.